<%--
  Created by IntelliJ IDEA.
  User: lenovo
  Date: 2024/11/22
  Time: 10:54
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java"
         pageEncoding="utf-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
    <title>welcome.jsp</title>
</head>
<body>
  <form action="${pageContext.request.contextPath}/welcome.jsp">
    <c:if test="${empty param.num1}">
      姓名:<input type="text" name="num1">
          <input type="submit" value="submit"/><br/>
    </c:if>

    <c:if test="${not empty param.num1}">
          ${param.num1 }<br/>
    </c:if>
  </form>
</body>
</html>
